4. Maintenance
USE AND MAINTENANCE MANUAL
CHAPTER 4
MAINTENANCE
XEF 250 - Rev01 / 2020
72
1
2
5
6
1
3
2
4
FWD
– Tighten each bolt by turning it 60° with respect to the initial
reference, following the 1st Phase tightening order;
Head bolts “1” – “4”:
Specified angle = 60°
4th Phase
– Mark a second reference between the bolt and the head,
then tighten each bolt by a further 60° following the
tightening order of the 1st Phase;
Head bolts “1” – “4”:
Specified angle = 60°
– Tighten the nuts “5” and “6” to the specified torque.
Nuts “5” – “6”:
10 Nm (1.0 m•kg, 7.4 ft•lb)
The head bolts tightening must be completed in four
steps, as described below:
1st Phase
– Tighten the head bolts to the specified torque by
performing the operation in two/three steps, following the
diagram shown in the figure.
Head bolts “1” – “4”:
30 Nm (3.0 m•kg, 22 ft•lb)
2nd Phase
– Remove a single bolt, following the tightening order;
– Apply molybdenum disulphide grease again to the thread
and contact surface of the bolt and washer;
– Tighten the bolt to the specified torque;
Head bolts “1” – “4”:
15 Nm (1.5 m•kg, 11 ft•lb)
Perform the 2nd Phase operations one bolt at a time.
Remove the bolts in the order used for tightening,
then tighten them according to the new tightening
torque.
3rd Phase
– Using a marker pen, mark a reference between bolt “1” and
head “2”;
